There are a few drawbacks of an AC compared to a DC powered lift. First, the AC motor controller will heat up faster and cut back the power to the motor if the lift truck is used to push loads or climb a lot of ramps. The second thning is that the AC motors are new to lift trucks, at least in the US. Replacement motors and motor controllers will be more expensive than convetional DC motors. The third thing is the the power consuption of a AC truck is only about 3% less than a comparable DC truck.

The AC trucks I have seen do not have enclosed motors and Many DC motor trucks are now pwered by MOFSETS.

I can see a definate advantage to having an AC motor in an explosion proof truck. All DC motors produce sparks at the brushes. The AC motors do not.

I assume the above minor drawbacks of the AC motor powered lift trucks will be overcome and the AC motor will be much more common.

In the US, the common battery voltage is 36 or 48 volts. Euerope is 72 to 80 volts. The heat problem with the motor controller I mentioned may not be a factor in Europe. I'm all for not having to replace those nasty black carbon brushes.